import time
incomplete_sign = 50
print('='*23+'开始下载'+'='*25)
for i  in range(incomplete_sign+1):
    completed = "*"*i
    incomplete = "."*(incomplete_sign - i)
    percentage = (i/incomplete_sign)*100
    print("\r{:0f}%[{}{}]".format(percentage,completed,incomplete),end="")
    time.sleep(0.5)
print("\n"+'='*23+'下载完成'+'='*25)